axa_axa

Detailed Description

axa_axa contains top-level macros, datatype definitions and function declarations.

Data Structures
struct	axa_emsg_t
	AXA error message datatype. More...

Macros
#define	AXA_DIM(_a)   ((int)((sizeof(_a) / sizeof((_a)[0]))))
	Return the number of elements in an array. More...
#define	AXA_LAST(_a)   (&(_a)[AXA_DIM(_a)-1])
	Return a pointer to the last item of an array. More...
#define	AXA_OFFSET(_p, _s, _t)
	Produce a pointer to a byte in a buffer that corresponds to a structure tag. More...
#define	AXA_IS_WHITE(c)
	Test a char to see if it's whitespace. More...
#define	AXA_IS_UPPER(c)   ({char _c = (c); _c >= 'A' && _c <= 'Z';})
	test if char is uppercase More...
#define	AXA_IS_LOWER(c)   ({char _c = (c); _c >= 'a' && _c <= 'z';})
	test if char is lowercase More...
#define	AXA_IS_DIGIT(c)   ({char _c = (c); _c >= '0' && _c <= '9';})
	test if char is base 10 digit More...
#define	AXA_TO_LOWER(c)   ({char _l = (c); AXA_IS_UPPER(_l) ? (_l+'a'-'A') : _l;})
	convert char to lowercase More...
#define	AXA_TO_UPPER(c)   ({char _u = (c); AXA_IS_LOWER(_u) ? (_u-'a'-'A') : _u;})
	convert char to uppercase More...
#define	AXA_UNUSED   __attribute__((unused))
	Tell the compiler not to complain about an unused parameter. More...
#define	AXA_PF(f, l)   __attribute__((format(printf,f,l)))
	Tell the compiler to check an actual format string against the other actual parameters. More...
#define	AXA_NORETURN   __attribute__((__noreturn__))
	Tell the compiler that this function will never return. More...
#define	dcl_max(a, b)   ((a) >= (b) ? (a) : (b))
	Return the larger of two scalar values. More...
#define	AXA_CLITCMP(_b, _s)   (strncasecmp((_b), (_s), sizeof(_s)-1) == 0)
	Case compare two NULL terminated strings, comparing at most sizeof(_s - 1) characters. More...
#define	AXA_SALLOC(t)   ((t *)axa_zalloc(sizeof(t)))
	A calloc() wrapper that returns zero-filled memory of size sizeof (t) that is cast to (t *). More...
#define	AXA_DEBUG_WATCH   2
	generate trace syslog messages about watches, anomalies, and channels More...
#define	AXA_DEBUG_TRACE   3
	also generate trace syslog messages about client AXA messages and non-routine AXA messages More...
#define	AXA_DEBUG_MORE_TRACE   4
	also generate trace syslog messages about routine AXA messages and transport related messages such as from ssh More...
#define	AXA_DEBUG_NMSG   5
	also generate trace syslog messages from libnmsg and client-to-server rate limiting or congestion More...
#define	AXA_DEBUG_TO_NMSG(lvl)
	convert AXA debug level to NMSG debug level More...
#define	AXA_DEBUG_MAX   10
	maximum debugging level More...
#define	AXA_ASSERT_MSG(c, p, ...)
	Crash with a message if a condition is false. More...
#define	AXA_ASSERT(c)   AXA_ASSERT_MSG((c), "\""#c"\" is false")
	Crash if a condition is false. More...
#define	AXA_FAIL(...)   axa_fatal_msg(0, __VA_ARGS__)
	Crash with a message. More...
#define	AXA_DAY_SECS   (24*60*60)
	one day of seconds More...
#define	AXA_DAY_MS   (AXA_DAY_SECS*1000)
	one day of milliseconds More...

Enumerations
enum	axa_syslog_type_t
	AXA syslog types. More...

Functions
const char *	axa_domain_to_str (const uint8_t *src, size_t src_len, char *dst, size_t dst_len)
	Convert a domain name to a canonical string. More...
void *	axa_malloc (size_t s)
	A malloc() wrapper that crashes immediately (via AXA_ASSERT()) on malloc failures. More...
void *	axa_zalloc (size_t s)
	A calloc() wrapper that crashes immediately (via AXA_ASSERT()) on malloc failures. More...
char *	axa_strdup (const char *s)
	A strdup() wrapper that crashes immediately (via AXA_ASSERT()) on failure. More...
char *	axa_strndup (const char *s, size_t len)
	A strndup() wrapper that crashes immediately (via AXA_ASSERT()) on failure. More...
void	axa_vasprintf (char **bufp, const char *p, va_list args)
	A vasprintf() wrapper that crashes immediately (via AXA_ASSERT()) on vasprintf failures. More...
void	axa_asprintf (char **bufp, const char *p,...) AXA_PF(2
	An asprintf() wrapper that crashes immediately (via AXA_ASSERT()) on asprintf failures. More...
void void	axa_set_core (void)
	Try to enable core files. More...
void	axa_set_me (const char *me)
	Set the global program name before axa_syslog_init() is called. More...
bool	axa_parse_log_opt (axa_emsg_t *emsg, const char *arg)
	Parse and set logging options before calling axa_syslog_init() More...
void	axa_syslog_init (void)
	Initialize the AXA syslog interface. More...
void	axa_buf_print (char **bufp, size_t *buf_lenp, const char *p,...) AXA_PF(3
	Add text to an error or other message buffer. More...
void void	axa_clean_stdio (void)
	prevent surprises via use of stdio FDs by ensuring that the FDs are open to at least /dev/null More...
void	axa_vpemsg (axa_emsg_t *emsg, const char *msg, va_list args)
	Generate an error message string in a buffer, if we have a buffer. More...
void	axa_pemsg (axa_emsg_t *emsg, const char *msg,...) AXA_PF(2
	axa_vpemsg() wrapper using the variadic stdarg macros (va_start(), va_end()). More...
void	axa_vlog_msg (axa_syslog_type_t type, bool fatal, const char *p, va_list args)
	Log an AXA message. More...
void	axa_verror_msg (const char *p, va_list args)
	Log or print an error message. More...
void	axa_error_msg (const char *p,...) AXA_PF(1
	Log or print an error message. More...
void void	axa_io_error (const char *op, const char *src, ssize_t len)
	Log an error message for an I/O function that has returned either a negative read or write length or the wrong length. More...
void	axa_vtrace_msg (const char *p, va_list args)
	Log a trace message in the tracing syslog stream as opposed to the error syslog stream. More...
void	axa_trace_msg (const char *p,...) AXA_PF(1
	Log a trace message in the tracing stream or AXA_SYSLOG_TRACE as opposed to the error or AXA_SYSLOG_ERROR stream. More...
void void	axa_vfatal_msg (int ex_code, const char *p, va_list args) AXA_NORETURN
	Log a serious error message and either exit with a specified exit code or crash if the exit code is EX_SOFTWARE. More...
void	axa_fatal_msg (int ex_code, const char *p,...) AXA_PF(2
	Log a serious error message and either exit with a specified exit code or crash if the exit code is EX_SOFTWARE. More...
char *	axa_fgetln (FILE *f, const char *file_name, uint *line_num, char **bufp, size_t *buf_sizep)
	Get a logical line from a stdio stream, with leading and trailing whitespace trimmed and "\\\n" deleted as a continuation. More...
const char *	axa_strip_white (const char *str, size_t *lenp)
	Strip leading and trailing white space. More...
ssize_t	axa_get_token (char *token, size_t token_len, const char **stringp, const char *seps)
	Copy the next token from a string to a buffer and return the size of the string put into the buffer. More...
uint32_t	axa_hash_divisor (uint32_t initial, bool smaller)
	Get a modulus for a hash function that is tolerably likely to be relatively prime to most inputs. More...
bool	axa_parse_ch (axa_emsg_t *emsg, uint16_t *chp, const char *str, size_t str_len, bool all_ok, bool number_ok)
	Parse a channel string into a binary channel in host byte order. More...
time_t	axa_tv_diff2ms (const struct timeval *tv1, const struct timeval *tv2)
	Compute (tv1 - tv2) in milliseconds, but limited or clamped to 1 day. More...
time_t	axa_elapsed_ms (const struct timeval *now, struct timeval *then)
	Compute the positive elapsed time between two timevals in milliseconds, but limited or clamped to at least 0 ms and at most 1 day. More...
const char *	axa_get_version (void)
	Retrieve the semantic library version as a string. More...
uint32_t	axa_get_version_number (void)
	Retrieve the semantic library version as a packed integer. More...

Variables
void	AXA_NORETURN

Macro Definition Documentation

AXA_DIM

#define AXA_DIM

(

_a

)

((int)((sizeof(_a) / sizeof((_a)[0]))))

Return the number of elements in an array.

Parameters

[in]

_a

the array to size up

Returns

the size of the array as an int instead of size_t

AXA_LAST

#define AXA_LAST

(

_a

)

(&(_a)[AXA_DIM(_a)-1])

Return a pointer to the last item of an array.

Parameters

[in]

_a

the array containing the item

Returns

a pointer to the last item

AXA_OFFSET

#define AXA_OFFSET	(		_p,
			_s,
			_t
	)

Value:

                               ((uint8_t *)(_p)                         \
                               + ((uint8_t *)&((_s *)0)->_t  - (uint8_t *)0))

Produce a pointer to a byte in a buffer that corresponds to a structure tag.

This works where a cast to the structure would not work or would give the wrong answer because of word mis-alignment of the buffer or other reasons.

Parameters

[in]	_p	pointer to source data
[in]	_s	name of desired structure
[in]	_t	desired tag in the structure

Return values

pointer

to byte in source data corresponding to the tag. The pointer might not be properly aligned.

AXA_IS_WHITE

#define AXA_IS_WHITE

(

c

)

Value:

                                      ({char _c = (c); _c == ' ' || _c == '\t'  \
                                      || _c == '\r' || _c == '\n';})

Test a char to see if it's whitespace.

AXA ignores locales to get consistent results on all systems, and because the AXA control files are ASCII.

Parameters

[in]

c

char to test

Return values

1	if whitespace
0	if not

AXA_IS_UPPER

#define AXA_IS_UPPER

(

c

)

({char _c = (c); _c >= 'A' && _c <= 'Z';})

test if char is uppercase

Parameters

[in]

c

char to test

Return values

1	if uppercase char
0	if not

AXA_IS_LOWER

#define AXA_IS_LOWER

(

c

)

({char _c = (c); _c >= 'a' && _c <= 'z';})

test if char is lowercase

Parameters

[in]

c

char to test

Return values

1	if lowercase
0	if not

AXA_IS_DIGIT

#define AXA_IS_DIGIT

(

c

)

({char _c = (c); _c >= '0' && _c <= '9';})

test if char is base 10 digit

Parameters

[in]

c

char to test

Return values

1	if base 10 digit
0	if not

AXA_TO_LOWER

#define AXA_TO_LOWER

(

c

)

({char _l = (c); AXA_IS_UPPER(_l) ? (_l+'a'-'A') : _l;})

convert char to lowercase

Parameters

[in]

c

char to convert

Returns

the converted char if it was previously uppercase, c if not

AXA_TO_UPPER

#define AXA_TO_UPPER

(

c

)

({char _u = (c); AXA_IS_LOWER(_u) ? (_u-'a'-'A') : _u;})

convert char to uppercase

Parameters

[in]

c

char to convert

Returns

the converted char if it was previously lowercase, c if not

AXA_UNUSED

#define AXA_UNUSED   __attribute__((unused))

Tell the compiler not to complain about an unused parameter.

AXA_PF

#define AXA_PF	(		f,
			l
	)		__attribute__((format(printf,f,l)))

Tell the compiler to check an actual format string against the other actual parameters.

Parameters

[in]	f	the number of the "format string" parameter
[in]	l	the number of the first variadic parameter

AXA_NORETURN

#define AXA_NORETURN   __attribute__((__noreturn__))

Tell the compiler that this function will never return.

dcl_max

#define dcl_max	(		a,
			b
	)		((a) >= (b) ? (a) : (b))

Return the larger of two scalar values.

This macro is for declarations where ({}) is not allowed and side effects can't happen.

Parameters

[in]	a	first value to compare
[in]	b	second value to compare

Returns

the larger of the two values, if they are equal, return a

AXA_CLITCMP

#define AXA_CLITCMP	(		_b,
			_s
	)		(strncasecmp((_b), (_s), sizeof(_s)-1) == 0)

Case compare two NULL terminated strings, comparing at most sizeof(_s - 1) characters.

Parameters

[in]	_b	const char * first, not necessarily null terminated string to compare
[in]	_s	const char * null terminated second string to compare

Returns

same semantics as strncasecmp()

AXA_SALLOC

#define AXA_SALLOC

(

t

)

((t *)axa_zalloc(sizeof(t)))

A calloc() wrapper that returns zero-filled memory of size sizeof (t) that is cast to (t *).

Parameters

[in]

t

object to allocate memory for

Returns

pointer to the allocated memory

AXA_DEBUG_WATCH

#define AXA_DEBUG_WATCH   2

generate trace syslog messages about watches, anomalies, and channels

AXA_DEBUG_TRACE

#define AXA_DEBUG_TRACE   3

also generate trace syslog messages about client AXA messages and non-routine AXA messages

AXA_DEBUG_MORE_TRACE

#define AXA_DEBUG_MORE_TRACE   4

also generate trace syslog messages about routine AXA messages and transport related messages such as from ssh

AXA_DEBUG_NMSG

#define AXA_DEBUG_NMSG   5

also generate trace syslog messages from libnmsg and client-to-server rate limiting or congestion

AXA_DEBUG_TO_NMSG

#define AXA_DEBUG_TO_NMSG

(

lvl

)

Value:

                                              nmsg_set_debug((lvl) <= AXA_DEBUG_NMSG    \
                                              ? 0 : ((lvl)-AXA_DEBUG_NMSG))

convert AXA debug level to NMSG debug level

AXA_DEBUG_MAX

#define AXA_DEBUG_MAX   10

maximum debugging level

AXA_ASSERT_MSG

#define AXA_ASSERT_MSG	(		c,
			p,
			...
	)

Value:

                                 ((c) ? 0                                   \
                                 : axa_fatal_msg(0, __FILE__":%d " p,       \
                                                 __LINE__, ##__VA_ARGS__))

Crash with a message if a condition is false.

AXA_ASSERT_MSG() can have required side effects such as stopping on a fatal condition, and so cannot be #ifdef'ed out.

Parameters

[in]	c	condition to assert
[in]	p	pattern or message
[in]	...	optional variadic arguments for pattern parameters)

AXA_ASSERT

#define AXA_ASSERT

(

c

)

AXA_ASSERT_MSG((c), "\""#c"\" is false")

Crash if a condition is false.

AXA_ASSERT() can have required side effects, usually stopping on a fatal condition.

Parameters

[in]

c

condition to assert

AXA_FAIL

#define AXA_FAIL

(

...

)

axa_fatal_msg(0, __VA_ARGS__)

Crash with a message.

Parameters

[in]

...

variadic arguments

AXA_DAY_SECS

#define AXA_DAY_SECS   (24*60*60)

one day of seconds

AXA_DAY_MS

#define AXA_DAY_MS   (AXA_DAY_SECS*1000)

one day of milliseconds

Enumeration Type Documentation

axa_syslog_type_t

enum axa_syslog_type_t

AXA syslog types.

Enumerator
AXA_SYSLOG_TRACE	trace
AXA_SYSLOG_ERROR	error
AXA_SYSLOG_ACCT	accounting

Function Documentation

axa_domain_to_str()

const char* axa_domain_to_str	(	const uint8_t *	src,
		size_t	src_len,
		char *	dst,
		size_t	dst_len
	)

Convert a domain name to a canonical string.

Sane wrapper for wdns_domain_to_str(). dst_len must be >=NS_MAXDNAME because wdns_domain_to_str() does not check.

Parameters

[in]	src	domain name in wire format
[in]	src_len	length of domain name in bytes
[out]	dst	caller allocated string buffer that should be of size NS_MAXDNAME
[in]	dst_len	size of the dst buffer

Returns

the value of dst

axa_malloc()

void* axa_malloc

(

size_t

s

)

A malloc() wrapper that crashes immediately (via AXA_ASSERT()) on malloc failures.

Parameters

[in]

s

size of memory to allocate

Returns

pointer to the allocated memory

axa_zalloc()

void* axa_zalloc

(

size_t

s

)

A calloc() wrapper that crashes immediately (via AXA_ASSERT()) on malloc failures.

The memory region will be zero-filled.

Parameters

[in]

s

size of memory to allocate

Returns

pointer to the allocated memory

axa_strdup()

char* axa_strdup

(

const char *

s

)

A strdup() wrapper that crashes immediately (via AXA_ASSERT()) on failure.

The caller must free() the result.

Parameters

[in]

s

the string to duplicate

Returns

pointer to the duplicated string

axa_strndup()

char* axa_strndup	(	const char *	s,
		size_t	len
	)

A strndup() wrapper that crashes immediately (via AXA_ASSERT()) on failure.

The caller must free() the result.

Parameters

[in]	s	the string to duplicate
[in]	len	length of string

Returns

pointer to the duplicated string

axa_vasprintf()

void axa_vasprintf	(	char **	bufp,
		const char *	p,
		va_list	args
	)

A vasprintf() wrapper that crashes immediately (via AXA_ASSERT()) on vasprintf failures.

When you're done with it, bufp should be freed.

Parameters

[out]	bufp	a pointer to the newly minted and formatted string
[in]	p	the format string
[in]	args	a var args list

axa_asprintf()

void axa_asprintf	(	char **	bufp,
		const char *	p,
			...
	)

An asprintf() wrapper that crashes immediately (via AXA_ASSERT()) on asprintf failures.

When you're done with it, bufp should be freed.

Parameters

[out]	bufp	a pointer to the newly minted and formatted string
[in]	p	the format string
[in]	...	a var args list

axa_set_core()

void void axa_set_core

(

void

)

Try to enable core files.

Wraps getrlimit() and setrlimit().

axa_set_me()

void axa_set_me

(

const char *

me

)

Set the global program name before axa_syslog_init() is called.

Parameters

[in]

me

argv[0]

axa_parse_log_opt()

bool axa_parse_log_opt	(	axa_emsg_t *	emsg,
		const char *	arg
	)

Parse and set logging options before calling axa_syslog_init()

Parameters

[out]	emsg	error message if something is wrong
[in]	arg	comma separated string with the following options: {trace|error|acct},{off|FACILITY.LEVEL}[,{none,stderr,stdout}] {trace|error|acct} selects one of three streams of information "off" or "FACILITY.LEVEL" disable or turn on syslog for the chosen "trace", "error" and "acct" streams. {none,stderr,stdout} directs the stream independently of how it is sent to the system log. A stream can be sent to either, both, or neither the system log and stderr or stdout.

The following settings for "trace", "error" and "acct" are assumed to send the "trace" and "error" streams to the system log and stderr and the "acct" stream to only the system log: trace,LOG_DEBUG.LOG_DAEMON error.LOG_ERR,LOG_DAEMON acct,LOG_NOTICE.LOG_AUTH,none

Return values

true	if string is valid
false	if not

axa_syslog_init()

void axa_syslog_init

(

void

)

Initialize the AXA syslog interface.

Call this function after calling axa_parse_log_opt() and axa_set_me(), and before calling any AXA logging, accounting, or tracing function.

axa_buf_print()

void axa_buf_print	(	char **	bufp,
		size_t *	buf_lenp,
		const char *	p,
			...
	)

Add text to an error or other message buffer.

If we run out of room, add "...".

Parameters

[in,out]	bufp	in: the original string, out: the concatenated strings
[in,out]	buf_lenp	in: the length of bufp string, out: new length
[in]	p	the format string to copy over
[in]	...	va_args business

axa_clean_stdio()

void void axa_clean_stdio

(

void

)

prevent surprises via use of stdio FDs by ensuring that the FDs are open to at least /dev/null

axa_vpemsg()

void axa_vpemsg	(	axa_emsg_t *	emsg,
		const char *	msg,
		va_list	args
	)

Generate an error message string in a buffer, if we have a buffer.

Log or print the message with axa_vlog_msg() if there is no buffer.

Parameters

[out]	emsg	if something goes wrong, this will contain the reason
[in]	msg	message
[in]	args	arguments to p

axa_pemsg()

void axa_pemsg	(	axa_emsg_t *	emsg,
		const char *	msg,
			...
	)

axa_vpemsg() wrapper using the variadic stdarg macros (va_start(), va_end()).

Parameters

[out]	emsg	if something goes wrong, this will contain the reason
[in]	msg	message
[in]	...	variable length argument list

axa_vlog_msg()

void axa_vlog_msg	(	axa_syslog_type_t	type,
		bool	fatal,
		const char *	p,
		va_list	args
	)

Log an AXA message.

Depending on type and calls to axa_parse_log_opt(), this function could write to stdout stderr, and/or syslog.

Parameters

[in]	type	one of axa_syslog_type_t
[in]	fatal	if true and fatal verbiage will be prepended to message
[in]	p	message
[in]	args	variadic argument list

axa_verror_msg()

void axa_verror_msg	(	const char *	p,
		va_list	args
	)

Log or print an error message.

This is a wrapper for axa_vlog_msg() with type of AXA_SYSLOG_ERROR with fatal == false.

Parameters

[in]	p	message
[in]	args	variadic argument list

axa_error_msg()

void axa_error_msg	(	const char *	p,
			...
	)

Log or print an error message.

This is a variadic wrapper for axa_vlog_msg() with type of AXA_SYSLOG_ERROR with fatal == false.

Parameters

[in]	p	message
[in]	...	variable length argument list

axa_io_error()

void void axa_io_error	(	const char *	op,
		const char *	src,
		ssize_t	len
	)

Log an error message for an I/O function that has returned either a negative read or write length or the wrong length.

Complain about a non-negative length or decode errno for a negative length.

Parameters

[in]	op	canonical string referring to the I/O event that caused the error
[in]	src	error message
[in]	len	length of src

axa_vtrace_msg()

void axa_vtrace_msg	(	const char *	p,
		va_list	args
	)

Log a trace message in the tracing syslog stream as opposed to the error syslog stream.

Parameters

[in]	p	message
[in]	args	variadic argument list

axa_trace_msg()

void axa_trace_msg	(	const char *	p,
			...
	)

Log a trace message in the tracing stream or AXA_SYSLOG_TRACE as opposed to the error or AXA_SYSLOG_ERROR stream.

Parameters

[in]	p	message
[in]	...	variable length argument list

axa_vfatal_msg()

void void axa_vfatal_msg	(	int	ex_code,
		const char *	p,
		va_list	args
	)

Log a serious error message and either exit with a specified exit code or crash if the exit code is EX_SOFTWARE.

Parameters

[in]	ex_code	exit code
[in]	p	message
[in]	args	variadic argument list

axa_fatal_msg()

void axa_fatal_msg	(	int	ex_code,
		const char *	p,
			...
	)

Log a serious error message and either exit with a specified exit code or crash if the exit code is EX_SOFTWARE.

Parameters

[in]	ex_code	exit code
[in]	p	our last words
[in]	...	va_args business

axa_fgetln()

char* axa_fgetln	(	FILE *	f,
		const char *	file_name,
		uint *	line_num,
		char **	bufp,
		size_t *	buf_sizep
	)

Get a logical line from a stdio stream, with leading and trailing whitespace trimmed and "\\\n" deleted as a continuation.

If the buffer is NULL or it is not big enough, it is freed and a new buffer is allocated. This must be freed by the caller after the last use of this function.

Except at error or EOF, the start of the next line is returned, which might not be at the start of the buffer.

Parameters

[in]	f	the file to read from (for error reporting)
[in]	file_name	name of the file (for error reporting)
[in,out]	line_num	line number of file, will be progressively updated
[in,out]	bufp	buffer to store line, can be NULL
[in,out]	buf_sizep	size of buffer pointed to by bufp

Returns

The return value is NULL and emsg->c[0]=='\0' at EOF or NULL and emsg->c[0]!='\0' after an error.

axa_strip_white()

const char* axa_strip_white	(	const char *	str,
		size_t *	lenp
	)

Strip leading and trailing white space.

Parameters

[in,out]	str	in: string to cleanse, out: cleansed string
[in,out]	lenp	in: length of the string, out: new length

Returns

the string cleansed of whitespace

axa_get_token()

ssize_t axa_get_token	(	char *	token,
		size_t	token_len,
		const char **	stringp,
		const char *	seps
	)

Copy the next token from a string to a buffer and return the size of the string put into the buffer.

Honor quotes and backslash. The caller must skip leading token separators (e.g. blanks) if necessary. When the separators include whitespace and whitespace ends the token, then all trailing whitespace is skipped.

Parameters

[in,out]	token	token goes here
[in,out]	token_len	length of the token
[in,out]	stringp	input string
[in,out]	seps	string of token separators

Returns

the size of the string, -1 on error

axa_hash_divisor()

uint32_t axa_hash_divisor	(	uint32_t	initial,
		bool	smaller
	)

Get a modulus for a hash function that is tolerably likely to be relatively prime to most inputs.

We get a prime for initial values not larger than 1 million. We often get a prime after that. This works well in practice for hash tables up to at least 100 million and better than a multiplicative hash.

The algorithm starts by finding either the smallest prime number that is larger than the initial parameter value and not larger than 1009 or the largest prime smaller than the initial value and not larger than 1009. The algorithm is finished if the initial value is at most 1009. Otherwise, it finds the smallest (or largest) number that is relatively prime to all prime numbers <=1009.

Parameters

[in]	initial	is the starting point for searching for number with no small divisors. That is usually the previous size of an expanding hash table or the initial guess for a new hash table.
[in]	smaller	false if you want a value smaller than the initial value.

Returns

the modulus

axa_parse_ch()

bool axa_parse_ch	(	axa_emsg_t *	emsg,
		uint16_t *	chp,
		const char *	str,
		size_t	str_len,
		bool	all_ok,
		bool	number_ok
	)

Parse a channel string into a binary channel in host byte order.

Parameters

[out]	emsg	if something goes wrong, this will contain the reason
[out]	chp	pointer to a axa_p_ch_t channel in host byte order
[in,out]	str	string containing channel number or "all" keyword
[in,out]	str_len	length of str
[in]	all_ok	boolean indicating "all" is allowed
[in]	number_ok	boolean indicating "202 is the same as ch202"

Return values

true	if no errors were encountered, chp will contain the channel
false	error was was encountered, emsg will contain the reason

axa_tv_diff2ms()

time_t axa_tv_diff2ms	(	const struct timeval *	tv1,
		const struct timeval *	tv2
	)

Compute (tv1 - tv2) in milliseconds, but limited or clamped to 1 day.

Parameters

[in]	tv1	const struct timeval * to first time value
[in]	tv2	const struct timeval * to second time value

Returns

the difference between the two tv_sec values, in ms

axa_elapsed_ms()

time_t axa_elapsed_ms	(	const struct timeval *	now,
		struct timeval *	then
	)

Compute the positive elapsed time between two timevals in milliseconds, but limited or clamped to at least 0 ms and at most 1 day.

Negative elapsed time implies that the system clock was set back. In that case, set the 'then' timestamp to 'now' and return 0.

Parameters

[in]	now	const struct timeval * current time
[in]	then	struct timeval * past value, which will be set to the current time if it in the future of the current time.

Returns

the difference between the two tv_sec values, in ms

axa_get_version()

const char* axa_get_version

(

void

)

Retrieve the semantic library version as a string.

axa_get_version_number()

uint32_t axa_get_version_number

(

void

)

Retrieve the semantic library version as a packed integer.

The number is a combination of the major, minor, and patchelevel numbers as per: MAJOR * 1000000 + MINOR * 1000 + PATCHLEVEL.